Adsorption refrigeration system



Aug. 1 8, 1942 A. B, NEWTON 2,293,556

I ADSORPTION REFRIGERATION SYSTEM Filed April 17, 1939 2 Sheets-Sheet l I05 we 68 92 18 v as 6| 52 63 60 I 90 as 6 15 8 82 e, 8 96- 7o '73 1| 0 8| 72 O 81 sq 6 5 5 4.- Znnenfor A1win B. Newton.

Aug. 18, 1942. A. B. NEWTON 2,293,556

ADSORPTION REFRIGERATION SYSTEM Filed April 1'7, 193 9 2 SheetsSheet 2 bummer rigs Alwin B. Newton.

E atenteei i8,

rarer 7 rater;v

ADSORETIGN REFRIGERATION SYS'EEM B. Newton, Minneapolis, Minn, assignor to Minneapclisloneywell itetor illompany, Minneapolis, Minn, a corporation of Deiaware Application an 117, race, Serial No. aeazaa 14 Claims.

This invention relates to a refrigeration system and more particularly to a control system for that type of refrigeration system known as an adsorption refrigeration system.

time of the objects of this invention is the provision of a control means for activating the adsorber of an adsorption refrigeration system.

More particularly it is an object of this invention to provide, in an adsorption refrigeration system, a heating means for activating the adsorber, means for placing the heating means in operation whenever the adsorber temperature is sufliciently low and the evaporator temperature is sufiiciently high and for terminatingoperation of the heating means when the adsorber temperature drops to'a predetermined value.

A further object of this invention is to pro vide, in an adsorption refrigeration system means for alternately adding heat to the adsorber for activating purposes, and reducing the temperature of the adsorber to reduce the pressure therein, initiating operation of the heating means whenever the adsorber temperature and the evaporator temperature are suficiently low, terminating operation of the heating means whenever the adsorber temperature rises to a predetermined value, and rendering the cooling means effective whenever the heating means isrendered inoperative.

Other objects and advantages of this invention will become apparent upon a study of the specification, claims, and appended drawings wherein like reference characters represent like parts in the various views and wherein Figure 1 is a schematic showing of an adsorption refrigeration system embodying the control features of my invention,

Figure 2 is a v'iew with certain parts in cross section of the valve for controlling the flow of fuel to the heating means, and the actuating means therefor,

Figure 3 is a view in cross section of the valve for controlling the cooling means for the adsorber, and

Figure 4 is a modification of the control system of Figure 1 applied to a refrigeration system ot. the same type as shown in Figurel.

Referring more particularly to Figure 1 the referenee character lll represents an evaporator which receives refrigerant from the receiver ll connected to the condenser l2 which is in turn connected to the adsorber l3. The adsorber l3 may be provided with any suitable adsorbing material such as activated carbon illustrated by the reference character It, The outlet of the 55 (ill. 62-5) evaporator iii communicates by means of the,

pipe i5 with the adsorber i3 and upon heating of the adsorber in order to activate the same, refrigerant flows into the evaporator ti) by way of the condenser l2, receiver ii and pipe iii. Reverse fiow of the refrigerant is prevented by the check valves i8 and it.

Located within the adsorber i3 is a heating coil 20 connected to the receptacle it which is 10 to be, heated, the coil 29 and receptacle 2i containing a suitable heat exchange medium which may be in the :ibrm of a volatile fluid and for this purpose a suitable refrigerating medium such as Carrene may be .utilized. Upon applying heat to the receptacle it the Carrene is vaporized and flows upwardly through pipes 22 and 23 into the coil in the'adsorber iii, the fluid returning to the receptacle it by way of the pipe 24 provided with a trap 25. it will be 20 apparent that as the fluid. in the receptacle 2i is heated and circulates through the coil 28 in the adsorber, the temperature of the adsorber will be increased and the refrigerant which has been adsorbed by the activated carbon therein 25 will be driven off and flow into the evaporator ill byway of the condenser l2.

Communicating with the receptacle 2! by way of the pipe 22 and the pipe 28 is a coil 38 which forms a cooling or heat dissipating coil and 30 which may be placed in any suitable location whereby it will be cooled by the surrounding medium. The outlet of this coil is connected to a valve 3|, the outlet of this valve communicating by means of the pipe 32 with the pipe 23. 35 The valve 3| is shown in detail in Figure 3 'and is seen to comprise an inlet opening 34 controlled by a valve element 35 which is normally biased to open position by means of the spring 36, a bellows 31 being operatively connected to 40 the valve element and being arranged to close heating the receptacle 2|, this tube, bulb, and

bellows being provided with a. fill-such as a suitable volatile fill. When the burner 42 is in operation the bulb 4| will be heated up and the volatile fill therein will cause expansion of the bellows 31 which'in turn causes the valve element 35 to close off the inlet port 34 so that any fluid which is in the coil 30 is not permitted to escape therefrom by way of this valve.

The burner 42 is supplied with a combustible fluid by way of a pipe 43 controlled'by a valve 44, there being a suitable pilot burner 55 connected to the inlet side of the valve for igniting the fuel issuing from the burner 42 when the valve 44 is opened. when the burner 42 is in operation the valve '3! controlling the heat dissipating coil 30 will be closed as described above. The fluid within the receptacle 2i will be vaporized and will pass by way of the pipes 22 and 23 into the heating coil 20 and will return by way of the pipe 24 to the receptacle 2|. At the same time the fluid being vaporized in 'the receptacle 2] will flow byway of the pipes 22 and 28 into the heat dissipating .coil 30 but will be prevented fromv leaving the coil since the valve 3| is at this time closed. The fluid will accordingly be trapped within the coil 30 and will condense therein. The refrigerant which has been adsorbed by the material within the adsorber 13 will be driven into the evaporator In by way of the condenser I2. After a certain length of time, substantially all of the refrigerant will have been driven out of the adsorber and the burner 42 willthen be shut oil by means to be hereinafter set forth. When the burner shuts oil the bulb Ii will cool down thus causing a reduction in pressure in the bellows 31 of the valve 3| so that this valve will now open. The fluid which has condensed in the coil 30 will now flow by way or the valve 3|, pipes 32, 23 into thecoil 2|! in the adsorher l3. The fluid in the coil 30 will be relatively cool compared to the temperature or the adsorbr so that this flow of the fluid from the coil 30 through the cooling coil "of the adsorber will reduce the temperature in the adsorber and consequently reduce the pressuretherein. As the pressure within the adsorber decreases the refrigerant in the evaporator will vaporize and flow back to the adsorber and the temperature of the evaporator I! will consequently decrease. The evaporator Ill therefore efieets refrigeration and the cooling eifect oi the evaporator will continue until all of the refrigerant therein has been drawn back into the adsorber I3. when this happens the temperature of the evaporator will again start to rise above the minimum value attained thereby and an activating cycle or the type described above will be resumed by means to be described.

Referring more particularly to Figure 2, the details of the valve 44 and operating mechanism therefor is illustrated. This valve is shown to include an inlet 5., an outlet SI, and a valve element 52 for controlling now from the inlet to the outlet thereof. The valve element 52 is tension .spring ll havm' g the adjusting means 18. lever 80 pivoted at 8! and having its right end biased upwardly by the tension spring 82 having means 83 for adjusting the tension thereof. The

- spring It on passing the dead center position lapses and the lever 55 moves upwardly it will. engage the member 90 located at the lower ex will cause the lever H to move downwardly with a snap action which will force the valve element 52 to its closed position against the force of the spring 55. As the bellows 8! coltremity of the compression spring 9|, provided with a suitable adjusting means 92 so that this spring oppose upward movement of the lever 65 after it has moved upwardly a short distance above the position illustrated. In order for the lever 65 to snap the lever ll back to the position illustrated, the lever 6! must move up- 'wardly' beyond the position illustrated in order to move the spring 10 back through the dead center position so that the pressure within the bellows 5| must be considerably less in order to cause the-lever H to move back to the posilion illustrated than existed therein when the' lever II was snapped downwardly since the spring 9| opposm the action of the spring 67. The amount that the pressure must be-reduced in the bellows GI will depend upon the adjustment of the spring 9| and accordingly this spring sealed from the operating chamber 53 by means of the diaphragm II and the valve element is S5. A housing Iii is located on top of the valve body and in the upper wall of thlshousing are suitably mounted operating bellows il, 2; and $3. The operating bellows I controls the p05- tion of a lever pivoted at 66 and biased upwardly by the tension spring 61 having a suitable adjusting means 68 for adjustingthe tension thereof. The end of the lever 65 remote from the pivot 66 is connected by means of a spring III to a lever II pivoted at 12, the spring HI and lever 65 forming a snap acting mechanism for the lever II. Upward movement of the lever H is limited by means of a suitable stop I2 and the extremity of the lever II overlies the top of the valve element 52.

The bellows 62 controls the position of a lever 15 pivoted at 16 and biased upwardly by the forms a differential adjustment for the lever H.

after the lever 65 has moved to the position 11- lustrated the 9| has no 'efiect thereon. It will be understood that these stops will be out of the path of movement of the lever 65. It will accordingly be seen that the valve 52 willbe closed whenever the pressure within the bellows 6| rises to a sufllciently high value and the valve cannot be. reopened until the .pressure within the bellows has dropped to a value substantially less than the closing pressure thereon.

As the bellows 62 expands and lever 15 is moved downwardly against the force of spring 11 the lever 85 will be moved downwardly, thus moving the valve towards closed position, but this lever is not operated with a snap action as is' the lever 1 I The spring 82 associated with the lever biases this lever in a direction to move the lever l5 downwardly and the action of this spring is opposed by an increase in pressure in the bellows 53. i It will be apparent therefore that the lever 85 will move downwardly as the' bellows 62 expands or as the bellows i3 collapses under the influence o! the spring '2 thus moving the valve toward.

closed position, or if the valve is closed by the lever :l, these bellows may prevent reopening The interior of the bellows 6| is connected by means of the capillary tube "It to a bulb "L The bellows 53 controls the position of a Suitable stops are provided for limiting downward movement of the member-SI so that closed position.

lows SI will expand and when the temperature of the -adsorber rises to a sufliciently high value,

'such'as225 F. the bellows 6| will have expanded sufliciently to move the lever 1! down with a snap action, thus moving the valve element 52 to be opened again when the temperature of the adsorber drops sufilciently,

" The interior of the bellows 62 is connected by means of the tube with the interior of the receptacle2l so that if the pressure within this .receptacle rises sutilciently such as to a value of Iil lbs. sq. inch, the bellows 62 will expand causing downward movement of the lever 85 through the lever and consequent moving of the valve element towards closed position, thus reducing or cutting oil? the supply of fuel to the burner 42 so that the pressure within the receptacle 2| will not increase to a dangerous value.

The interior of the bellows i3 is connected by means of-the capillary tube IIG to the bulb IIII which may be located in contact with the evapo rator I II to sense the temperature thereof; the tube, bulb and bellows having a suitable fill.so

that the bellows 63' will expand or contract in response to increases or decreases in the temperature ofthe evaporator I0. Whenever the temperature of the evaporator is above a certain value as 28 F. the bellows 63 will be sufiiciently expanded so that the lever" does not exert any closing force on the valve 52 through thelever 85 but as the temperature of the evaporator drops below this value and the bellows 63 contracts, the

spring 82 will be eflective to move the inner end of the lever 80 downwardly thus causing the valve 52 to move towards closed position.

Assume now that the heater l2 isjin operation for activating the adsorber at which time the valve and operating means therefor are in the positions illustrated. The temperature of the adsorber will gradually increase and after the temperature has risen to a value such as 225 F. which is an indication that substantially all of the adsorbed refrigerant has been driven out of the adsorber, the expansion of the bellows BI will move the valve 52 to closed position with a snap action. Thetemperature of the evaporator will now start to decrease as explained heretofore and the temperature will decrease rather rapidly causing a collapse of the bellows 63 so that the lever Blunder the influence of the 82 will hold the lever 85 downwardly in valve closing position. This action will take place rather rapidly and before the temperature of the adsorber has decreased to the value at which lever II is moved back to the position illustrated. The

' valve is thus at this time held closed both by reason of the low evaporator temperature and the high adsorber temperature. As the temper ature of the adsorber decreases to a relatively low value as 150 the lever II snap upwardly but if the evaporator temperature is still sufiiciently low the valve 52 will be held closed by the spring 82 acting on the lever 80. As the evaporator. II] becomes emptied of refrigerant which has been adsorbed by the adsorber I3 the temperature thereof will start to rise rapidly and after it has risen to a suiliciently high value such as 26 F. the bellows 63 will have expanded sutr 2,993,556 increase in temperature of the adsorber the bel- When the temperature of the w ficiently to overcome the tension of the spring 82 and if the adsorber temperature is suiiiciently low at this time as it will be in the normal operation of the system, the valve 52 will be reopened thus 5 initiating a new activating cycle of the system. The valve 31 will now close under the influence of heat mm the burner 42 thus trappinga new charge of fluid in the condenser 30 as heretofore described. If at any time during the activating l0 cycle the pressure within the receptacle 2I becomes excessive the bellows 62 will be expanded and will overcome the tension of the spring 11 to move the valve 52 to its closed, position. This excessive pressure will not normally be attained 15 during the operation of the system but this operating bellows 62 is provided as a safety measure.

It will thus be seen that with the system described in Figure 1 the valve 44 controlling the 63 which respond to the adsorber temperature, I

the pressure in'the receptacle 2I and evaporator temperature, respectively, in a'manner to automatically and effectively controlthe activating and cooling "cycles of the refrigeration system, in conjunction with the valve 3| controlling the condenser or heat dissipating coil 30.

Referring now to Figure 4, an electrically controlled valve I II! is provided for controlling the flow. of fuel to the burner 42. A motor III is provided for controlling-the operation oi this valve and this motor may be of any suitable construction such as a solenoid which when energized causes opening of the valve III! and when deenergized permits the valve to close under the influence of gravity or any suitable biasing means 7 (not shown). V

For controlling the solenoid II! mercury switches H5, HS, and Ill are provided. The 4o position of the switch I15 is controlled by the bellows I20 which responds to the pressure within the receptacle 2i and when this pressure rises sufficiently the bellows I20 moves the switch ME to circuit breakingposition against the tension of the spring I24.

The switch I I6 is controlled by a bellows 522 connected by means of the capillary tube I2:'l

with the bulb I24 positioned to respond to the temperature of the adsorber I3, thetube, bulb and bellows being provided with a suitable fill so that when the temperature of the adsorber rises sufficiently the expansion of the bellows I22 will move the switch 6 to the circuit breaking position. This switch is a wide difierentialswitch and may be curved longitudinally as illustrated so that the mercury element in the switch will be moved to the circuit making position when the temperature of the adsorber drops to a value such as 150 F. and will not move to circuit break- 60 ing position until the temperature of the adsorber has risen to some high value such as 225 F. It will be understood of course that any other suitable arrangement may be utilized for obtainin a wide operating difierential of the switch IIB vices of Figure 1.

orator temperature rises to some value such as With the switches I I5, I I6, and I II in the posi-= tions illustrated, power is supplied to thejvalve motor or solenoid III by way .of conductor I40,

2,293,550 I invention is ,to be limitedonly by the scope 20f the appended claims. Y

I claim as my invention:

" an evaporator operatively connected together,

creasing to open the switch III so this switch will remain closed during the activating cycle.

Should'the pressure within receptacle 2| become excessive which will happen onlyunder abnormal conditions, the switch II5 will open,'deenergizing solenoid I I I- and interrupting vthe activating cycle. Normally however the activating cycle will continue until the temperature of the adsorber rises to a high value such as 225 F. whereupon switch 5 will be moved to open position thus' deenergizing solenoid III and closing valve IIII. When the valve 'I II) closes, a refrigerating cycle will commence as explained in connection with Figure 1 and at this time the evaporator temperature will rapidly decrease and the switch I" will move to pen position before the adsorber temperature drops sufliciently to cause closure of the switch II6. Accordingly the refrigerating or cooling cycle will continue until 'both the adsorber temperature decreases to a -predetermined value such as 150 F. and the trolling the flow of refrigerant evaporator temperature rises to a high value such as 28 F. which will happen very soon after the evaporator III has been emptied of its refrigerant. Accordingly the system shown in this figure accomplishes electrically exactly what is accomplished by the direct acting pressure de- In the outlet of the evaporator .III is provided a valve I50 biased by means of a spring I5I towards closed position. A bellows I52 exerts an opening force on the valve I50 when the temperature of the evaporator rises, this bellows being connected by the capillary tube I53 to the bulb I51 located in contactwith the evaporator to sense the temperature thereof. The valve I58 accordingly operates to control the flow of refrigerant from the evaporator in a manner to maintain a substantially constant evaporator temperature during the cooling period-thereof. Itshould be understood that this valve may also be applied to the system of Figure l or if desired this valve may be eliminated from the system shown in Figure 4. Moreover, the bulb I54 'may respond to boxtemperature inste d of evaporator temperature if desired to maintain a constant box temperature.

It will thus be seen that I have completely automatic control system for use with an adsorption type refrigeration system for controlling the activating and cooling cycles thereof either electrically or bydirect acting pressure responsive mechanism and it will be understoodthat any equivalent type of control arrangement may be utilized without departing from the spirit and scope of the present invention. Also many modifications ofthe details illustrated herein may become apparent to those skilled in the art and it should therefore be understood that this provided a heating means for activating the adsorber, means responsive to'thetemperature of the adsorberand the temperature of the evaporator for initiating operation of the heating means and responsive to the temperature of the adsorber for terminating operation of the heating means, and means responsive to the temperature ,of the evaporator for controlling the flow of refrigerant therethrough. I

2. In an adsorption refrigeration system of the class described, an adsorber, at condenser and an evaporator operatively connected together, means for heating the adsorber, means for cooling the adsorber, means responsive to the temperature of the adsorber and the temperature of the evaporator for initiating operation of the heating means and responsive to the temperature of the adsorber for terminating operation of the heating means, means responsiveto operation of the heating means for interrupting operation of the cooling means, and means responsive to the temperature of the evaporator for conthrough the evaporator. 4 v

3. In anadsorption refrigeration system of the class described, an adsorber, a. condenser andan evaporator 'operatively connected together, heat exchanger means associated with said adsorber for adding heat thereto or extracting heat therefrom, said heat exchanger means including a heat exchanger coil associated with said adsorber,

heating-means for supplying heat to a medium circulating through said heat exchanger coil, cooling means for cooling said adsorber, control means for controlling the operation of the heating means, said control means including means for initiating operation of the heating means in response to a low adsorber temperature and a high evaporator temperature and for terminating operation of the heating means in response to a high adsorber temperature, and means responsive to. operation of the heating means for rendering said cooling means ineffective.

v 4. In an adsorption refrigeration system of the kind described, an adsorber, a condenser and an evaporator operatively connected together, means for activating the adsorber and for causing a reduction of a pressure thereimsaid means in- I eluding a fluid'fuel burner, valve means for controlling the flow of fuel to said burner, a plurality of pressure responsive means acting directly on said valve means to control the .posi, tion thereof, means rendering one of said pressure responsive means responsive to a pressure corresponding to the temperature of the adsorber, means rendering a second .of said pres.- sure responsive means responsive to the temperature of the evaporator, means causing. said one pressure responsive means to close the valve means when the absorber temperature attainsa predetermined high value and preventing opening of the'valve means until the adsorber temperature drops to-a value substantially lower than the value at which the valve means was closed, and means causing the second of said pressure responsive means to maintain the valve means in its closed position until the temperature of the evaporator has risen to a predetermined value.

1. In an adsorption refrigeration system of the ,class described, an adsorber, a condenser and tion thereof, means rendering one of said pres-- sure responsive means responsive to the temperature of the adsorber, means rendering a second of said pressure responsive means responsive to the temperature of the evaporator, means rendering a third of said pressure responsive means responsive to the pressure of said heat exchange medium, means causing said one pressure responsive means to close the valve means when the adsorber temperature attains a predetermined high value and preventing opening of the valve means until the adsorber temperature drops to a value substantially lower than the value at which the valve means was closed,

means causing the second of said pressure responsive means to maintain the valve means in its closed position until the temperature of the evaporator has risen to a predetermined value, and means causing said third pressure responsive means'to move the valve means towardsclosed position as the pressure of the heat exchange medium becomes excessive.

6. In an adsorption refrigeration system of the kind described, an adsorber, a condenser and an evaporator operatively connected together, heating means for activating the adsorber, electrically operated means for causing operation of the heating means in response to the energization thereof, a control circuit for saidelectrically operated means including a first switch means responsive to the temperature of the adsorber, said switching means having a relatively wide difierential and a second switch means responsive to the temperature of the evaporator, said first switch means being arranged to close in response to a low adsorber temperature, said second switch means being arranged to' close when the temperature of the evaporator rises above 'a predetermined value, and said first switch means being arranged to open in response to a relatively high adsorber temperature.

7. In an adsorption refrigeration system ofthe kind described, an adsorber, a condenser and an evaporator operatively connected together, heating means for activating the adsorber, electrically operated means for causing operation of the heating means in response to the energization thereof, a control circuit for said electrically op-' erated means including a first wide differential switch means responsiveto the temperature of the adsorber and a second narrow differential switch means responsive to the temperatureof the evaporator, said first switch means being arranged to close in response to a low adsorber temperature and said second switch means being arranged to close when the temperature of the evaporator rises above a predetermined value, and means responsive to the temperature of said evaporator for controlling the flow of refrigerant therefrom.

8. In an adsorption refrigeration system of the class described, an adsorber, a condenser and an evaporator operatively connected together, a heat exchanger. system including a heatexchanger coil within said adsorber containinga heat exchange medium ln the form of a volatile fluid, means for heating the heat exchange medium passing through said coil, a heat dissipating coil located externally of said adsorber and in communication with said heat exchanger coil, control means for the heating means, said control means including means rendering the heating means inoperative in response either to the attainment of a predetermined temperature within the adsorber or an excessive pressure within said heat exchanger system and rendering the heating means effective only if the temperature of the evaporator is sufficiently high, the temperature of the adsorber is sufficiently low and the pressure in the heat exchanger system is sufliciently low, valve means controlling the flow of the heat exchange medium through the heat dissipating coil, and means responsive to the operation of said heating means for causing the closure of said valve means.

9. In apparatus of the character described, in combination, means adapted to give ofi a refrigerant when heated and to take up said refrigerant when cooling, an evaporator connected in fluid flow relationship with said means, a heat source associated with said means, means controlling said heat source including anelectric. circuit having a switch means therein responsive to the temperature of said first means and arranged to' close at a relatively low temperature thereof and to open at a relatively high temperature thereof and a switch means in said circuit responsive to evaporator temperature and arranged to close at a relatively high temperature thereof, v

10. In apparatus of the character-described, in combination, means adapted to give off a refrigerant when heated and to take up said refrigerant when cooling, an evaporator connected in fluid flow relationship with said means, a heat source associated with said means, means controlling said heat source including an electric cir-= cuit having a switch means therein responsive to is a measure of the temperature of said heat source.

11. In apparatus of the character described, in combination, means adapted to give oil a refrigerant when heated and to take up said refrigerant when cooling, an evaporator connected in fluid new relationship with said means, a heat source associated with said means, means controlling said heat source including a valve, means responsive to the temperature of said means for abruptly closing said valve at a predetermined relatively high temperature thereof, means responsive to the temperature of the evaporator arranged to graduatingly open the valve as the evaporator temperature rises, said means responsive to the temperature of the first means being arranged to permit opening of the valve if the temperature of the first means is below said predetermined temperature,

12. In apparatus of the character described, in combination, means adapted to give off a refrigerant when heated and to' take up said refrigerant when cooling, an evaporator connected in fluid flow relationship withsaid means, a heat predetermined temp rature,

orator arranged to graduatingly open the valve as the evaporator temperature rises, said means responsive to-the temperature of the first means being arranged to permit opening of the valve if the temperature of the first means is below said and additional means responsive to a condition which is a measure of the temperature of the heat source for closme said valve. V

13. In an adsorption refrigeration system of the class described, an adsorber, a. condenser and an evaporator operatively connected together, means for changing the temperature of said adsorber, means cooperating with the first mentioned means for causing the latter to cool the adsorber, and means responsive to a condition brought about by the need for reactivation v of the adsorber for rendering the second mentioned means inoperative.

14. In an adsorption refrigeration system of the class described, an adsorber, a condenser and an evaporator operatively connected together, means for changing the temperature of said ad 'sorber, means cooperating with the first mentioned means for causing the latter to cool the adsorber. and means responsive to the temperature of the adsorber for renderingthe second mentioned means inoperative.

ALWIN B. NEWTON. 

